Five carbon materials, including multi-walled carbon nanotubes (MWCNT), carbon aerogel (CARF), carbon black (Vulcan carbon), activated carbon (AC), and graphite, were used as supports of the carbon-supported Ru catalysts, and the hydrodeoxygenation of lignin-derived monomers and lignocellulose pyrolysis oil was performed. Ru/MWCNT exhibited the highest deoxygenation activity, and the origin of the improved catalytic activity was studied. The metal dispersion, the acidity as measured by means of temperature-programmed desorption, the pore structure, and the surface area were investigated in an effort to understand the catalysis results. We observed that the quantity of accessible Ru nanoparticles on the mesopores determined the hydrodeoxygenation activity.